Lock for revolving chair base



Sept. 30, 1958 M. FOX 2,854,065

LOCK FOR REVOLVING CHAIR BASE Filed Jan. 30, 1957 United States Patent LOCK FOR REVOLVING CHAIR BASE Martin Fox, Chicago, Ill., assignor to The Seng Company, a corporation of Illinois Application January 30, 1957, Serial No. 637,173

3 Claims. (Cl. 155-95) This invention relates to a revolving chair base, and in particular it relates to such a base which is provided with a lock for preventing rotation of the turntable.

The principal object of the invention is to provide a revolving chair base having a turntable, and a simple and inexpensive lock for preventing rotation of the turntable.

Another object of the invention is to provide a screw type lock for the turntable of a revolving chair which may be easily set and released by a person seated in the chair.

Yet another object of the invention is to provide a screw type lock for a turntable which has a lower plate of substantially larger diameter than its upper plate.

The invention is illustrated in a preferred embodiment in the accompanying drawings in which:

Fig. 1 is a front elevational view of a revolving chair base embodying the invention, with the conventional legs and chair parts in light lines;

Fig. 2 is a fragmentary section taken the line 22 of Fig. 1; and

Fig. 3 is a sectional view of the lock bracket, taken as indicated along the line 33 of Fig. 2, with the screw removed.

Referring to the drawings in greater detail, a chair base has a turntable indicated generally at 5 which conas indicated along sists of a lower plate 6, and an upper plate 7 revolubly secured thereto by means of an axially positioned loose n'vet 8. The upper and lower plates have registering annular grooves 9 and 10, respectively, which cooperate to form a ball race to receive conventional anti-friction bearings.

The lower plate 6 is substantially larger in diameter than the upper plate 7 so that it may have a plurality of legs L bolted to it outside the margin of the upper plate.

The upper plate 7 has four radial ears 11 provided with oval holes 12 to receive wood screws 13 by means of which a rectangular chair seat supporting member 14 may be fixedly secured surmounting the turntable. As seen in Fig. 1, the seat supporting member 14 extends beyond the margin of the lower plate 6, and is adapted to receive and support a chair seat and back structure, indicated generally at C.

A brake device for preventing rotation of the turntable includes a brake supporting bracket, indicated generally at 15, which has an attaching plate 16 secured to the supporting member 14 by means of wood screws 17. Flanking the attaching plate 16 are parallel, depending arms 18 and 19, and in said arms are registering apertures 20 and 21, respectively, the centers of which are on an extension of a radius of the lower plate 6, and the aperture 21 has a thread 21a.

Extending through the apertures 20 and 21 is a hand screw 22 the shaft 23 of which has a thread 24 engaging the thread 21a. and shaft 23 has a flat end 25 which may 2,854,065 Patented Sept. 30, 1958 be abutted against the margin of lower plate 6 to prevent rotation of the turntable when desired. The screw 22 has a hand wheel 26 which is seen in Fig. l to be positioned outside the margin of supporting member 14 where it may be easily reached by a person sitting in the chair, in order to lock or release the turntable by turning the screw.

The foregoing detailed description is given for clearness of understanding only and no unnecessary limitations are to be understood therefrom, as modifications will be obvious to those skilled in the art.

I claim: I

l. A revolving chair base comprising: a ballbearing turntable including upper and lower relatively revoluble plates, said lower plate having an unobstructed circular margin and being adapted to have a plurality of legs secured thereto; axially positioned means revolubly securing said plates together; a chair seat supporting member surmounting said turntable and extending laterally beyond the margin thereof; depending brake supporting bracket means on said supporting member, said bracket means having a horizontal threaded aperture in the plane of the lower plate; and a hand brake screw in said aperture the inner end of which is adapted to frictionally engage the margin of the lower plate to selectively lock the turntable against rotation, said screw having a hand wheel outside the margin of the supporting member.

2. A revolving chair base comprising: a ballbearing turntable including upper and lower relatively revoluble plates, said lower plate having an unobstructed circular margin and being adapted to have a plurality of legs secured thereto; axially positioned means revolubly securing said plates together; a chair seat supporting member surmounting said turntable and extending laterally beyond the margin thereof; a brake supporting bracket having an attaching plate portion secured to said supporting member and a pair of parallel depending arms which have registering apertures the centers of which are on an extension of a radius of the lower plate, one of said apertures being threaded; and a hand brake screw in said apertures, said screw having a flat inner end which is adapted to frictionally engage the margin of the lower plate to selectively lock the turntable against rotation, and having a hand wheel outside the margin of the supporting member.

3. A revolving chair base comprising: a ballbearing turntable including upper and lower relatively revoluble plates, said lower plate being of substantially larger diameter than said upper plate having an unobstructed circular margin and being adapted to have a plurality of legs secured thereto; axially positioned means revolubly securing said plates together; a chair seat supporting member surmounting said turntable and extending laterally beyond the margin of the lower plate; a brake supporting bracket having an attaching plate portion secured to said supporting member flanked by a pair of parallel depending arms which have registering apertures the centers of which are on an extension of a radius of the lower plate, one of said apertures being threaded; and a hand brake screw in said apertures, said screw having a flat inner end which is adapted to frictionally engage the margin of the lower plate to selectively lock the turntable against rotation, and having a hand wheel outside the margin of the supporting member.

References Cited in the file of this patent UNITED STATES PATENTS 

